splunk_escuHunting

Windows BootLoader Inventory

The following analytic identifies the bootloader paths on Windows endpoints. It leverages a PowerShell Scripted input to capture this data, which is then processed and aggregated using Splunk. Monitoring bootloader paths is significant for a SOC as it helps detect unauthorized modifications that could indicate bootkits or other persistent threats. If confirmed malicious, such activity could allow attackers to maintain persistence, bypass security controls, and potentially control the boot process, leading to full system compromise.

MITRE ATT&CK

T1542.001

Detection Query

`bootloader_inventory`
  | stats count min(_time) as firstTime max(_time) as lastTime values(_raw)
    BY host
  | `security_content_ctime(firstTime)`
  | `security_content_ctime(lastTime)`
  | `windows_bootloader_inventory_filter`

Author

Michael Haag, Splunk

Created

2026-02-25

References

Tags

BlackLotus CampaignWindows BootKits

Raw Content

name: Windows BootLoader Inventory
id: 4f7e3913-4db3-4ccd-afe4-31198982305d
version: 7
date: '2026-02-25'
author: Michael Haag, Splunk
status: experimental
type: Hunting
data_source: []
description: The following analytic identifies the bootloader paths on Windows endpoints. It leverages a PowerShell Scripted input to capture this data, which is then processed and aggregated using Splunk. Monitoring bootloader paths is significant for a SOC as it helps detect unauthorized modifications that could indicate bootkits or other persistent threats. If confirmed malicious, such activity could allow attackers to maintain persistence, bypass security controls, and potentially control the boot process, leading to full system compromise.
search: |-
    `bootloader_inventory`
      | stats count min(_time) as firstTime max(_time) as lastTime values(_raw)
        BY host
      | `security_content_ctime(firstTime)`
      | `security_content_ctime(lastTime)`
      | `windows_bootloader_inventory_filter`
how_to_implement: To implement this analytic, a new stanza will need to be added to a inputs.conf and deployed to all or some Windows endpoints. https://gist.github.com/MHaggis/26518cd2844b0e03de6126660bb45707 provides the stanza. If modifying the sourcetype, be sure to update the Macro for this analytic. Recommend running it daily, or weekly, depending on threat model.
known_false_positives: No false positives here, only bootloaders. Filter as needed or create a lookup as a baseline.
references:
    - https://gist.github.com/MHaggis/26518cd2844b0e03de6126660bb45707
    - https://www.microsoft.com/en-us/security/blog/2023/04/11/guidance-for-investigating-attacks-using-cve-2022-21894-the-blacklotus-campaign/
tags:
    analytic_story:
        - BlackLotus Campaign
        - Windows BootKits
    asset_type: Endpoint
    atomic_guid: []
    mitre_attack_id:
        - T1542.001
    product:
        - Splunk Enterprise
        - Splunk Enterprise Security
        - Splunk Cloud
    security_domain: endpoint